I want to implement a new cisco switch to our environment.
On site I have two HP switches connected.
One HP 24 port switch is connected over the fiber uplink with another HP 48 port switch.
The trunk or tagged port is 23.
The new Cisco switch is also a 48 port switch (2960S-TS-S)
This new switch is conncted over the second fiber uplink from the HP 24 port switch.
But when I set port 21 to tagged on the new CISCO switch nothing works anymore.
I thought it must be a trunk, because I have vlans on all switches.
Can you explain why its not working with a trunk ?